PDF(Pubmed)
Abstract：
Maintaining cellular calcium (Ca2+) homeostasis is essential for many aspects of cellular life. The high-osmolarity glycerol (HOG) mitogen-activated protein kinase (MAPK) pathway responsible for signal integration and transduction plays crucial roles in environmental adaptation, especially in the response to osmotic stress. Hog1 is activated by transient Ca2+ increase in yeast, but the functions of the HOG pathway in Ca2+ homeostasis are largely unknown. We found that the HOG pathway was involved in the regulation of Ca2+ homeostasis in Fusarium graminearum, a devastating fungal pathogen of cereal crops. The deletion mutants of HOG pathway displayed increased sensitivity to Ca2+ and FK506, and elevated intracellular Ca2+ content. Ca2+ treatment induced the phosphorylation of FgHog1, and the phosphorylated FgHog1 was transported into the nucleus by importin β FgNmd5. Moreover, the increased phosphorylation and nuclear accumulation of FgHog1 upon Ca2+ treatment is independent of the calcineurin pathway that is conserved and downstream of the Ca2+ signal. Taken together, this study reported the novel function of FgHog1 in the regulation of Ca2+ homeostasis in F. graminearum, which advance the understanding of the HOG pathway and the association between the HOG and calcineurin pathways in fungi.
摘要：
维持细胞钙（Ca2）稳态对于细胞生命的许多方面至关重要。高渗透压甘油（HOG）丝裂原活化蛋白激酶（MAPK）通路负责信号整合和转导在环境适应中起着至关重要的作用。尤其是对渗透胁迫的反应。Hog1被酵母中短暂的Ca2+增加激活，但HOG途径在Ca2+稳态中的功能在很大程度上是未知的。我们发现HOG通路参与了禾谷镰刀菌Ca2+稳态的调节,谷类作物的毁灭性真菌病原体。HOG途径的缺失突变体对Ca2和FK506的敏感性增加，细胞内Ca2含量升高。Ca2处理诱导了FgHog1的磷酸化，磷酸化的FgHog1被导入蛋白βFgNmd5转运到细胞核中。此外，在Ca2+处理后,FgHog1的磷酸化和核积累的增加独立于钙调磷酸酶途径,该途径是保守的和Ca2+信号的下游。一起来看,这项研究报道了FgHog1在调节F中Ca2稳态中的新功能。这促进了对HOG途径的理解以及HOG与真菌中钙调磷酸酶途径之间的关联。
